Well tester



Feb. 3, 1953 R. BAKER 2,627,317

WELL TESTER Filed Dec. 9, 1947 5 Sheets-Sheet l l, mi l In INVENTOR. @gaaf/v C. 54x51?,

,4U-ommen Feb. 3, 1953 Filed Dec. sa,I 1947 5 Sheets-Sheet Z5 160P4 4 e ea@ ww www ewvww7awv A INVENToR. ,Qa/@fw C. 54x52, BY

Patented Feb. 3, 1953 WELL TESTER Reuben C. Baker, Coalinga, Calif., assigner to Baker Oil Tools, Inc., Vernon, Calif., a corporation of California.

Application December 9, 1947, Serial No. 790,519

17 Claims. 1

The present invention pertains to sub-surface well tools, and more particularly to testers for determining the sealing eiiiciency of cement or plastic materials, after they have set and hardened behind casing or liners, or for determining the productivity of oil or gas formations.

In well testers of certain types, such as those adapted to be set in well -casings or liners, the tester is run in the well bore on the end of a tubular string, a valve mechanism preventing the well fluid from entering the tester and tubing string. The tester includes a packer designed to seal against the casing or liner wall and prevents the hydrostatic head of drilling mud or other casing uid from being imposed upon the formation being tested.

Usually the tester is run in the well bore with the packer retracted and the valve closed. As indicated above, the tubing string is normally dry, although under some conditions it may be partially iilled with a liquid. Upon reaching the point at which the testing operation is to occur, the packer is expanded against the casing and the tester valve is then opened, to allow the formation fluid, if any, to flow through the tester into the tubing' string to which itis connected. `After the valve has remained open for a predetermined time, any huid that may have passed through the tester is entrapped therein and in the tubing string. This fluid sample is then withdrawn with the tester to the top of the well bore.

It is an object of the present invention to genera-ily improve Well testers of the character indicated.

Another object of the invention is to provide an improved valve mechanism for controlling passage of fluid into or through the tester.

A. further object of the invention is to provide an improved valve mechanism, which can be repeatedly opened and closed, if desired, to determine iluid flow into and through the tester.

Still another object of the invention is to provide an improved tester valve mechanism, which can be opened at will to various extents while the tester is set in the well bore.

A further object of the invention is to provide a well packer having an improved valve device for controlling the by-passing of uid around the packing element of the packer, which effects a seal with the wall of a casing or liner in which it is positioned.

rl"he invention has other objects which will become apparent from a consideration of the embodiments shown in the drawings accompanying and constituting part of the present specification. These forms will now be described in detail to illustrate the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limited sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figures la and 1b together comprise an elevation oi a well tester in a casing string, with the parts in the position they occupy while the tool is being moved through the casing. Figure 1b actually forming a lower continuance of Figure la;

Figures 2h and 2c together constitute an enlarged longitudinal section through the tester, with the parts occupying the same relative position as in Figures la and lb;

Figures 3a., 3b and 3c are views similar to Figures 2a, 2b and 2c, illustrating the well tester With its parts in another operative position.

Figure 4- is a cross-section taken generally along the line -d on Figs. 1a and 2a;

Figure 5 is a cross-section taken generally along the line 5 5 on Figs. la and 2a;

Figure 6 is a cross-section taken generally along the line 9 6 on Fig. 2a;

Figure 'I is an exploded, elevational and sectional view of the cam mechanism for controlling the main valve of the tester.

Fig. 8 is a partial longitudinal section through a modiiied form of tester valve mechanism; and

Fig. 9 is a view similar to Fig. 8, with the parts in another operative position.

As disclosed in the drawings, the formation tester A is movable longitudinally through a well casing B on the lower end of a tubular string C, such as drill pipe or tubing. The formation tester A, includes a lower valve mechanism D, an intermediate packer E, and an upper control F for the valve and for setting and releasing the packer.

The Valve mechanism D is adapted to admit iiuid, or prevent iiuid from passing, into the tester A and tubing string C, and is capable of preventing such fluid from flowing out of the tubing string and tester. This valve mechanism includes a lower perforated or slotted nipple l0 of any desired length, having its bottom end closed by a cap H, and its upper end threaded into a sub i2 threaded into a valve housing i3. The upper end of the sub i2 is provided with a valve seat I4 adapted to be engaged by a valve element or ball l5 upon downward movement of the latter, to prevent downward flow o uid from the tester. This ball and seat l5, I4 actually constitute a check valve, with the ball movable upwardly from the seat to permit passage of fluid into the tester. Its extent of upward movement is limited by a stop the form of a pin i secured to and extending across the valve housing i3 above the ball l5.

Threaded or otherwise secured to the valve housing is a valve body il, having its upper end threadedly attached to the lower end of the tubular mandrel iE of the well packer Leakage between the body ll and housing i3 may be prevented by a side seal It, the latter engaging the inner wall of the body il.

The valve housing i3 contains a valve head 2i? adapted for upward movement into engagement with a valve seat 2l formed in the housing. A valve stem 22 is attached t0 and projects upwardly from the head, passing from the housing into the lower end of the valve body l l. Threaded on the upper end of the stem 122 is a spring retainer 23 secured in place by a suitable lock nut 24. The valve head tu is urged upwardly into engagement with its seat 2| by a helical oompression spring surrounding the valve stem 22, and coniined between the retainer 23 and a central boss integral with and projecting upwardly from the main portion of the valve housing i3. This boss has a plurality of generally radial ports 2l extending through its side wall, in order to establish communieation between a central chamber 28 in the valve housing i3, surrounding the valve stem 22, and the interior of the valve body il.

1t is apparent that the compressed spring normally tends to maintain the valve head 2li in an upward position in engagement with its seat 2|, to prevent iiuid from passing through the perforated nipple id and around the lower valve ball i5 into the valve body Il, from which it would otherwise continue travelling upwardly through the remainder of the tester and into the tubing string C. valve may ce opened at the will of the operator, located at the top of the well bore, upon downward movement of a valve rod 2li extending through the tubular packer mandrel i8. This valve rod is normally maintained and is urged in an upward direction by a relativels7 strong compression spring 3d, whose upper end is disposed within and engages a spring retainer 3l secured to the lower end of the valve rod 29, and whose lower end bears against the valve housing i3. The rod must be moved downwardly againstthe resisting force of the heavy return spring 3e, in order to move the main tester valve 2G downwardly against the force of its closing spring 25, thus opening the tester and permitting fluids to pass thereinto.

As described above, the operating rod 2S eX- tends through the packer mandrel it, there being substanti-l clearance between these elements to provide an annular passage through which fluids can iiow. This rod also extends through a sub or Yfacher valve member 3S threaded on the upper end ci the mandrel lil, and also through another sub Sil screwed into the Lipper of the previously mentioned sub. For the purpose of guiding the rod, which have a square cross-section, in its longitudinal movement within the mandrel ls and subs 34, a suitable ring or sleeve may be secured within the upper sub lill, as by the use of welding material 35, this ring slideably engaging the rod 29 and also having a hole therethrough of square cross-section. ln order to permit the fluid to Ilow upwardly around the rod, the guide ring or sleeve 35 has a plurality of circularly spaced holes 3l' therethrough.

The valve rod 29 is moved downwardly to open the main tester valve by a cam device forming part of the valve operating mechanism F. This device includes a lower driven face o1' axial cam Y38 disposed over the rod and having a shoulder 39 resting upon a companion shoulder at the upper end of the valve rod. The square crosssectional bore through the cam 33 below its shoulder ensures its coupling to the rod 2t. A complemental driving face or axial cam element di. is rotatable upon a cylindrical upper rod extension 23a, its lower cam surface Il! being engagerabel with the upper cam surface (i2 of the other element. One form of cam coniiguration is disclosed most clearly in Fig. '7, although other specic forms could be used.

The driving cam element t@ is welded, or otherwise suitably secured, to an inner tubular member 43 rotatable within an outer barrel 44 threaded on the upper sub 3d. The inner member 43 is prevented from moving longitudinally upward within the barrel 41% through engagement of a lower head l5 on the inner member with an intervening thrust washer 46, which, in turn, engages an inner shoulder tl on the barrel. Downward movement is prevented by a suitable thrust bearing 48 disposed between the lower end of the inner member 43 and the upper end of the upper sub 34. As illustrated in the drawings, this thrust bearing may include upper and lower races 49, 53 and intermediate tapered roller elements 5| in contact therewith.

It is apparent that the inner member t3 and the upper cam element @t secured thereto are rotatable with respect to the barrel 34, upper sub 34, lower cam element 38 and rod 29. Since the upper cam element i9 cannot move axially, its rotation produces downward axial movement of the other element 38 and valve rod 29, to effect opening of the main tester valve 2l).

The inner member i3 of the valve operating mechanism F is attached to the lower end of the tubing string C through the agency of a collar 52. This inner member 43 is also adapted to impart rotation, under some circumstances, to the outer barrel 41E, upper and lower subs tl, 33 and packer mandrel I8 through a slipping clutch. The latter includes a plurality of segments 53 having cylindrical inner faces irictionally engaging the exterior of the inner member t3, and downwardly and inwardly tapered external surfaces 54 engaging a companion tapered surface 55 at the upper end of the barrel 451. The segments 53 are preferably prevented from rotating relative to the barrel by one or more pins 56 secured to the barrel t4 and extending inwardly between a pair of adjacent segments.

The frictional coupling force between the segments 53 and inner member i3 is provided by a helical compression spring 5l disposed around the inner member, with its lower end bearing against the segments 53, to press them downwardly into the tapered portion 55 of the barrel and radially inward against the inner mandrel 533. The upper end of the spring 5l bears against an adjustment nut 58 threaded on the inner member and rotatable thereon to determine the degree of spring compression. This nut is held in adjusted position by a suitable lock nut 59.

The well packer which forms the intermediate part of the testing tool, includes the tubular mandrel I8 connected to the valve mechanism D and also to the valve control mechanism F',

'throughthe agency ofthe subs 33, 34. A tubular body 6I) surrounds the mandrel .in spaced relation Sto form an `annular passage S-I through which fluid may flow in by-passing a packing element 62, of rubber or similar material, surrounding the body and bearing at its upper end against a retainer and valve head 63 threaded on the body, and at its lower end against a ring 64 threaded on a tapered slip expander 65. The body 66 is movable downwardly with respect to the ring 64 i and expander 65 for the purpose of compressing the packing sleeve 62 and forcing it outwardly into leakproof engagement with the casing wall.

`Upward movement of the body relative to the ring and expander is limited by engagement of a body shoulder 66 wtha corresponding shoulder 61 on the ring 64. The expander 65, and mandrel are non-rotatably splined to each other by keys 99 secured to the mandrel slidable in keyways IUI) in the expander.

For the purpose of anchoring the tester at any desired location in the well casing, a plurality of slips 68 is mounted upon the tapered expander 65. These slips have inner faces 69 inclined in downward and inward direction, andslideable H along companion tapered faces or surfaces on the expander element 65. It is apparent that downward movement of the expander within the slips 68 shifts the latter radially outward and forces their external wickers 1| into the wall of the well casing B.

"In order to ensure conjoint movement of the slips 68, they are each pin connected to the upper end of a link 12, the lower end of which is pivotally mounted within a ring 13 loosely mounted upon the mandrel I8. This ring 13 is connected to the upper collar 14 of a drag and lock device l5 by means of a swivel connection 16, to permit rotation of the slip ring without rotating the drag device. As disclosed inthe drawings, this swivel connection may be constituted by a sectional tie ring 11 secured to the upper collar 14 of the drag device by screws 18 or the like. The tie ring including upper and lower inwardly directed flanges 19 disposed within companion external grooves in the slip ring 13 and collar 14, thereby providing the desired swivel connection permitting relative rotation between the slip ring and drag device, while ensuring their joint longitudinal movement.

The drag and lock device includes a lock pin 8l! secured to the mandrel I8 and movable `within a J or L slot, comprising a longitudinal portion 8| terminating in an upper horizontal locking portion 82. The drag device further includes a plurality of circularly spaced, outwardly `bowed springs 83 frictionally engaging thecasing wall, and having their upper ends secured to the collar 14, as by means of an encompassing ring 84 and set screws 85. Their lower ends are similarly secured to a lower collar 86 slideable upon the mandrel |8.

The annular passage 6| through the body .6.0 and around the packing element 62 may be closed by a valve device mounted upon the lower sub 33. 'Ihis Valve device has a cylindrical valve headl81 adapted to t snugly within a corresponding cylindrical valve seat 88 formed within the upper packing retainer 63 threaded on the body 66. 'Ihe valve head 81 is inserted into the seat 88 to the `extent determined by engagement of the lower end of the head with a shoulder 89 integral with the retainer 63.

Leakage between the cylindrical head 81 and seat 88 is prevented by one or more seal rings 8U.

. ing more than air `at atmospheric pressure.

`such as round rubber seals, carried within one or more ring kgrooves 9| in the head 81 and adapted to engage the cylindrical seat 88.

In order to protect the round seals 9|) of rubber or similar material while the head 81 is disposed out of the seat 88, or in open position, a protecting sleeve cover 92 is normally maintained over the seal or seals by a spring 93 sur-rounding the lower sub 33, with its lower end engaging the upper end of the sleeve cover 92, and its upper end engaging a shoulder 94 on the sub. The extent of downward movement of the cover along the sub under the action of the spring 93 is limited by engagement of a pin 95 secured to the sub 33 with the upper end of a longitudinal slot 86 in the sleeve 32.

Downward movement of the head 81 within the retainer 63 to close the by-pass passage 6| not only moves the head within the valve seat 88, but also causes the lower end 92a of the cover `92 to engage the upper end of the retainer 63 and move it relatively upwardly along the `sub against the action of the spring 93, until it has been removed fully from engagement with the round rubber seal or seals 98, allowing them to engage the cylindrical seat 88 and perform their sealing function. Upon elevation of the valve head 81 from its seat 88, to again expose the seals 90, the spring 93 shifts the cover 92 back over the seals 96 to protect them from damage.

The formation tester is made up atthe top of the well bore with the slips 6B and packing 62 in retracted positions, as determined by location of the mandrel lock pin within the horizontal locking portion 82 of the J or L slot. Withthe pin in this position, the slips and packing element are not only held in retracted positions, `but the valve head 81 is maintained in elevated `position above the mandrel seat 88, to hold the annular bypass passage 6| open. The cam elements `38, 46 have also been so disposed as to cause their longitudinal faces 91, 98 to co-engage, which ensures `disposition of the valve operating rod 28 in its uppermost position, in which the spring retainer 3| on the lower end of the rod is disengaged from `the valve stem 22, in order to allow the valve spring 25 to close the valve head 2B.

The tool .is mounted on the lower end of the tubular string C and is run in the well` casing B with the parts relatively related as just described and as illustrated in Figures l and 2. Ordinarily, the tubing string C and interior of the tester A above the main valve D are dry, containing noth- 0ccasionally, as in known in the art, some-uid may `be placed in the tubing string after the tester has been run through the drilling mud or other cas'- `ing fluid to a certain depth. When the point.' in

as to the right, the rotational force being transl mitted from the tubing string to the tubular inner member 43, and, by virtue of the frictional engagement of the latter with the segments 53, to the upper barrel 44, which, in turn, transmits the rotation through the upper and lower subs 34, 33 to the packer mandrel I8. Rotation of this mandrel moves its lock pin 80 out of the horizontal lock slot portion 82 and into the longitudinal slot portion 8|.

The tubing string C may now be lowered, causing the mandrel I8 to be lowered, its lock pin 88 moving downwardly within the longitudinal `slot 8|. The upper lock collar 14 containing the slot will not move downwardly, since such motion is Avalve head 2U with its seat 2|.

springs 83 with the casing B. During lowering movement of the mandrel I8 and the sub 33 connected thereto, the valve head tl is moved into the cylindrical valve seat 88, to close the by" pass passage 6|, until the end of the head Sl engages the retainer shoulder 89. Continued downward movement of the mandrel and sub connected to it then moves the retainer G3, tubular body 6%, packing element 62 and tapered expander 65 downwardly, shiftingthe last-mentioned part within the slips 58, which are prevented from downward movement by the drag device l5. As a result, the slips 53 are forced outward into anchoring engagement with the well casing B, in view of the wedging action of the expander 65, preventing further downward movement of the latter.

Additional downward movement of the tubing string C will now move the retainer and abutment member 63 and packer body 69 downwardly relative to the expander 65, compressing the packing sleeve 62 in the longitudinal direction and expanding it radially outward into rm sealing engagement with the casing B, to close the annulus between the well packer E and casing.

' Packing off of the annulus around the well packer and testing tool thus relieves the formation to be tested of the hydrostatic head of uid in the well casing above the tester and ensures :I

the passage of fluid into the tester when its main valve D is opened, in the event the formation pressure is greater than the atmospheric pressure in the tubing string.

Following the anchoring of the well tester in 'packed-olf condition within the well casing B,

the main tester valve D can be opened through Jrotation of the tubing string C, as to the right.

Such rotation is transmitted through lthe inner tubular member 43 to the upper cam 43, which cannot move longitudinally, and which, therefore, moves the lower cam 38 and valve rod 29 longitudinally against the force of the spring 30, to cause engagement of the retainer 3| with the valve stem 22 and shifting of the valve head 2l] down against the force of its closing spring 25. The tester is now open and any iiuid in the formation can flow into it through the perforated nipple |t,-to unseat the lower valve ball I and pass around the open valve head into the central valve chamber 28, from which it can flow through the ports 21 upwardly around the spring retainer 3| and through the annulus 32 around the valve rod, 29. In flowing upwardly around -the valve rod, the formation fluid passes through the holes 3'! in the guide ring 35, laround the cam elements 38, 40, and through the holes 40a in the upper element into the inner tubular member 43, from where it will pass into the tubing string C.

The tubing string is rotated less than a complete revolution, in the particular design illustrated in the drawings, to effect full opening of the main valve D. When it is desired to close the main valve to prevent further :dow of formation fluid into the tester, rotation of the tubing string C is continued in the same direction until the opposed faces 4|, 42 o f the cams ride oi one another, as when the longitudinal -faces 91, 98 are in substantial alignment with one another. The high point 42a on the lower cam is then opposite the low point Ila of the upper cam, which allows the return spring 39 to shift the rod 29 upwardly to its initial position, and permits the valve spring to re-engage the main As assurance 8 that the main valve will be closed, the tubing string C may be rotated slightly to the left, after having partaken of a complete revolution, to positively re-engage the longitudinal camfaces 91, 98 with one another.

The tester may now be released and withdrawn from the well casing. All that need be done ls to elevate the tubing string C, which willmove the valve head 81 out of the cylindrical seat 88, opening the by-pass passage I6 and equalizing the hydrostatic pressure on both sides of the packing element 62. Continued upward movement of the tubing string moves the upper retainer 63 away from the lower expander 65 yand allows the packing element to retract to its initial position free from contact with the casing wall. Further upward movement of the tubing string causes the keys 99 secured to the mandrel I8, to engage the upper expander ring 64 and pull the expander 65 upwardly with respect to the slips 68, since the latter are restrained from similar movement by engagement of the drag springs 83 with the casing B. This action retracts the slips from the casing in view of their dovetailed connection with the expander.

The elements of the tool are now in condition for withdrawal of the tester to the top of the well casing. Any ind that may have entered the tester and tubing string are prevented from iiowing out of the tester by downward closing of the valve ball I5 against its seat I4. If desired, the tubing string C may be rotated slightly to the left to reposition the lock pin in the horizontal slot portion 82, to hold the parts locked in their retracted positions during elevation of the tool within the well casing.

Because of the conguration of the coengaging cam elements 38, 49, the operating rod 29 and the main valve head 20 may be moved downwardly to Various extents, when the tester is anchored in pack-off condition within the casing B, depending upon the extent of rotation of the driving cam 43 with respect to the driven cam 38. It is apparent from an inspection of the figures, and particularly Fig. 7, that a slight angular movement of the driving cam 40 will effect movement of the valve rod and valve head to a comparatively slight extent, to correspondingly open the main valve head 2|) slightly.

As the angular movement of the driving cam 4|) increases, the extent of valve head opening also increases, until a maximum is reached, wherein the high points 4 la, 42a of the two cams are on the verge of riding olf one another, which will occur after substantially a complete revolution of the driving cam 40. A slight turning of the later beyond one full revolution will cause the high points to ride olf one another, and will allow the heavy spring 30 to shift the rod 29 back to its initial position, and allow the valve spring 25 to re-engage the valve head 20 with its seat 2 l, thereby closing the main valve D.

After the main Valve has been closed, it can be re-opened by merely continuing rotation of the tubing string C and the driving cam 4Q in the proper direction, as to the right. For that matter, the tubing string and driving cam connected to it may be rotated as often as desired, to effect alternate opening and closing of the main valve D. Thus, the main valve may be opened repeatedly, if desired, through a simple manipulation of the tubular string, and the extent of opening can be regulated in dependence upon the degree of angular movement of the tubing string C and the driving cam 40 from the initial position of the latter, with its longitudinal face 9T in full bearing contact with the corresponding longttudinal face 98 of the driven cam 38,

Following anchoring of the well packer E in pack-off condition Within the well casing B, it is evident that the packer mandrel I8 is prevented from rotating since the slips 68` are embedded in the casing wall, and in view of their dove--` tailed connection with the expander 65, prevent its downward movement and rotation in either direction. The slideable splined connection between the mandrel I3 and the tapered expander 65 in the form of the keys 99 and slots |00 prevents the mandrel i8 from rotating. As a result of preventing the mandrel from rotation upon anchoring of the slips 65 in the casing B, the upper and lower subs 34, 33 are also prevented from rotation, which precludes rotation of the valve rod 2e, in view of its square or rectangular cross-section and its slideable fit in the guide 35 welded to the upper sub 34.

Accordingly, after the well packer E has been anchored to the casing B, the outer barrel d4 connected to the sub 315 and the driven cam 38 are prevented from rotating. Rotary movement of the inner tubular member R3 is still capable of occurring to rotate the driving cam d without rotating the barrel, because of the ability of the inner tubular member 43 to slip within the friction clutch segments 53.

Before anchoring of the well packer E to the casing B, however, all parts, with the exception of the drag device l5, are free from engagement with the casing. The segments 53 of the clutch exert sufficient frictional force against the inner tubular member 43 to cause its rotary movement to be imparted, without slippage, to the barrel 44, and from the latter member, through the subs 35, 33 to the mandrel i8, enabling the lock pin 8B to be moved from the horizontal lock por tion 82 of the collar lil, whereupon the tubing string C may be lowered to cause the by-pass valve 8l, 88 to be closed, the slips 65 to be anchored in the casing, and the packing element 62 to be fore-shortened and expanded againstthe casing wall. Thereafter, as above indicated, the inner tubular member 43 slips within the clutch segments 53, for the purpose of rotating the driving cam 4t with respect to the driven cam 38 and determine the opening and closing of the main tester valve D.

The efficiency of the valve device for controlling the by-pass passage 6l around the packing element 62, and its long life before replacement is necessitated, is indicated by the fact that the elastic seal ring 90 is not subject to compression due to the down weight imposed upon the tubing string C in setting the well packer in the casing. The only load impressed upon the seal ring is that of the hydrostatic head of fluid in the annulus above the packing element 62, and the formation pressure acting in an upward direction. In addition, the sealing element 90 is not exposed when the valve is in open position in view of the protection afforded by the retractable sleeve cover 92. Assurance is therefore had that the seal ring 90 will be in proper condition for entry into and sealing against the cylindrical seat 8B when the by-pass valve is to be closed.

Under some conditionsI encountered in the well bore, it is desired to pump fluid through the tester and into the formation. As an example, during the testing operation, the Well may begin flowing under high pressure, and it may become necessary to kill the well by pumping a iluent substance down the tubing string C.

The valve mechanism disclosed in Figs. l to 7 inclusive, does not permit downward pumping of fluid through the tubing string, since the ball valve l5 moves downwardly into sealing engagement with its seat i4. The valve mechanism illustrated in Figs. 8 and 9 permits downward pumping of fluids, while allowing the formation tester to function in its normal manner, as described in connection with the other embodiment of the invention.

As shown in Figs. 8 and 9, the valve housing 13a is threaded into the valve body IT. The perforated nipple lila may be threaded into the lower end of the housing. In order to prevent downward ilow of fluids, under normal opera-` tion of the formation tester, the` ball valve I5 moves downwardly into engagement with a companion seat 14a formed in a sleeve valve l ID slide ably mounted in the valve housing Iia.. This sleeve valve is normally disposed over side ports Ill in the valve housing by one or more shear screws ll2, there being a suitable side seal H3 mounted on the sleeve valve l I0 for engagement with the valve housing above the ports III (see Fig. 8).

The valve mechanism operates in the 'same manner as the valve mechanism disclosed in the other embodiment of the invention. However, should it be necessary to pump fluids downwardly through the tubing string for outward passage from the formation tester below its packer E, the tubing string is lled with iluid. Sufficient pressure is imposed on this fluid to shear the screws |l2 and shift the sleeve valve H0 downwardly to a position limited by :its en gagement with the upper end of the perforated nipple (Fig. 9). In this position, the ports Ill are open and the fluids can be pumped outwardly from the valve mechanism through them.

The shear screws Il2 have suflicient strength to withstand a high hydrostatic head of iuid in the tubing string, in order to insure retention of the formation sample therein under normal use of the tester, The application of additional pressure to the fluid in the tubing string effects a shearing of the screws H2 and opening of the side ports III.

The inventor claims:

l. A well tester: including imperforate tubular means on a tubular string and adapted to conduct uid to said tubular string; valve means in said tubular means for controlling fluid ilow into said tubular means; means for opening and .closing said valve means, comprising a driven axial cam operatively connected to said valve means, a driving axial cam engageable with said driven axial cam, means for connecting said driving axial cam to said tubular string for manipulation thereby, and spring means engaging one of said cams to maintain said cams in engagement with each other when said valve means is closed.

2. A well tester: including imperforate tubular means on a tubular string and adapted to conduct fluid to said tubular string; valve means in said tubular means for controlling fluid flow into said tubular means; means for opening and closing said valve means, comprising an axial cam member and a follower member engageable therewith, one of said members being operatively connected to said valve means, means for connecting the other of said members to said tubular string for manipulation by said tubular 11 string, and spring means engaging said one of said members to maintain said members in engagement with each other when said valve means is closed.

3. A well tester: including tubular means on a tubular string and adapted to conduct fluid to said tubular string; valve means in said tubular means for controlling fluid flow into said tubular means; means for opening and closing said valve means, comprising a driven axial cam peratively connected to said valve means, a driving axial cam engageable with said driven axial cam, means for connecting said driving axial cam to said tubular string for rotation thereby in one direction to move said driven cam longitudinally in one direction to shift said valve means, said cams having coengaging tapered surfaces to effect alternate opening and closing of said valve means upon continuation in the rotation of said driving cam in the same direction through more than one revolution, and coengaging stop means on said cams to prevent longitudinal movement of said driven cam when said driving cam is rotated in the opposite direction.

4. A well tester: including tubular means on a tubular string and communicable with said tubular string to conduct fluid thereinto; valve means in said tubular means for controlling fluid iiow into said tubular means; means for opening and closing said valve means, comprising a spring for urging said valve means to closed position, a driven axial cam, means yconnecting said cam to said valve means, a driving axial cam engageable with said driven axial cam, means for attaching said driving axial cam to said tubular string for rotation thereby to move said driven cam longitudinally and open said valve means, and spring means engaging said connecting means to maintain said cams in engagement with each other when said valve means is closed.

5. A well tester; including tubular means on a tubular string and communicable with said tubular string to conduct fluid thereinto; valve means in said tubular means for controlling fluid iiow into said tubular means; and means for opening and closing said valve means, `comprising a driven axial cam operatively connected to said valve means, and a driving axial cam engageable with said driven axial cam, means for connecting said driving axial cam to said tubular string for manipulation thereby; and co-engaging stop means on said cams for limiting their relative rotation.

- 6. A well tester; including tubular means adapted to be lowered in a well bore; normally retracted means disposed around said tubular means and adapted for expansion into engagement with the wall of said well bore; lock means on said tubular` means for holding said normally retracted means in retracted position, said lock means being releasable by manipulation of said tubular means; a tubular member adapted for connection to a tubular string; releasable clutch means connecting said tubular member to said tubular means; valve means in said tubular means for controlling fluid flow into said tubular means; and means for opening and closing said valve means, comprising a driven axial cam connected to said valve means, and a driving axial cam engageable with said driven axial cam and connected to said tubular member.

7. A welltester; including tubular means adapted to be lowered in a well bore; normally retracted means disposed around said tubular means and adapted for expansion into engagement with the wall of said well bore; lock means on said tubular means for holding said normally retracted means in retracted position, said lock means being releasable by manipulation of said tubular means; a tubular member adapted for connection to a tubular string; releasable clutch means connecting said tubular member to said tubular means; valve means in said tubular means for controlling fluid flow into said tubular means; and means for opening and closing said valve means, comprising an axial cam member and a follower member engageable therewith, means connecting one of said members to said valve means and means connecting the other of said members to said tubular member.

8. A well tester; including tubular means adapted to be lowered in a well bore; normally retracted means disposed around said tubular means and adapted for expansion into engagement with the wall of said well bore; lock means on said tubular means for holding said normally retracted means in retracted position, said lock means being releasable by manipulation of said tubular means; a tubular member adapted for :connection to a tubular string; releasable clutch means connecting said tubular member to said tubular means; valve means in said tubular means for controlling fluid flow into said tubular means; and means for opening and closing said valve means, comprising a spring for closing said valve means, a cam member and a follower member engageable therewith, means connecting one of said members to said valve means, and means connecting the other of said members to said tubular member.

9. A well tester; including tubular means adapted to be lowered in a well bore; normally retracted means disposed around said tubular means and adapted for expansion into engage- Ament with the wall of said well bore; lock means on said tubular means for holding said normally retracted means in retracted position, said lock means being releasable by manipulation of said tubular means; a tubular member adapted for connection to a tubular string; releasable clutch means connecting saidtubular member to said tubular means; valve means in said tubular means for controlling fluid flow into said tubular means; and means for opening and closing said valve means, comprising a spring for closing said valve means, an axial cam member and a follower cam member engageable therewith, a rod extending through said tubular means and connecting one of said members with said valve means, and

ymeans connecting the other of said members to said tubular member for rotation therewith.

10. A well tester; including tubular means having a valve seat and adapted to be lowered in a well bore on a tubular string; valve means in said tubular means for controlling fluid iow between the interior and exterior of said tubular means, comprising a housing having a port therein, a sleeve valve adapted to be disposed over said port to close the same, means engageable with said sleeve valve to shift said sleeve valve to a position opening said port, a valve element movable upwardly into engagement with said valve seat to prevent upward flow of fluid into said tubular means, a downwardly closing valve device in said tubular means to prevent downward now of fluid from said tubular means, means for shifting said valve element between open and closed positions, comprising an axial cam member and a follower member engageable therewith, means connecting one of said members to said valve element, andmeans connecting the other` of said members to said tubular means.

` l'l A well tester; including tubular means having alvalve seat and adapted to be lowered in afwell bore on a tubular string; valve means in said tubular means for controlling uid flow between the interior and exterior of said tubular means, comprising a housing having a side port therein, asleeve valve having a seat, means releasably securing said sleeve valve to said housing and over said port, a first valve element above said sleeve valve and movable upwardly into engagement with said valve seat of said tubular means to prevent upward flow of fiuid into said tubular means, a second valve element movable 4downwardly into engagement with said sleeve valve seat to prevent downward flow of fluid from said tubular means through said sleeve valve, and means for shifting said first valve element between open and closed positions, comprising an axial cam member and a follower' member engageable therewith, means connecting one of said members to said first valve element, and means connecting the other of said members to said tubular means.

12. A well tester; including elongate tubular means on a tubular string and adapted to conduct fluid to said tubular string; valve means in said tubular means; a rod device within said tubular means engageable with said valve means to operate said valve means; a driven axial cam non-rotatably secured to said rod device; means for preventing substantial rotation of said rod device relative to said tubular means; a driving axial cam rotatable relative to said rod device and having a cam face engaging a companion cam face on said driven axial cam to re ciprocate the driven axial cam; means for preventing substantial movement in both longitudinal directions between said driving cam and tubular means; and means providing a connection for attaching said driving cam to said tubuiar string.

13. A well tester; including elongate tubular means on a tubular string and adapted to conduct fluid to said tubular string; a valve seat in said tubular means; a valve member engageable with said seat to prevent upward iiow of fluid into said tubular means above said seat; spring means within said tubular means urging said valve member upwardly; a rod device reciprocable within said tubular means and engageable with said valve member to shift said valve member downwardly from its seat; spring means engaging said rod device to elevate it from said valve member; a driven axial cam non-rotatably secured to said rod device; means for preventing substantial rotation of said rod device relative to said tubular means; a driving axial cam rotatable relative to said rod device and having a cam face engaging a companion cam face on said driven axial cam; means for preventing substantial longitudinal movement between said driving cam and tubular means; and means providing a connection for securing said driving cam to said tubular string.

14. A well tester; including tubular means adapted to be lowered in a well bore; normally retracted means disposed around said tubular means and adapted for expansion into engagement with the wall of said well bore; lock means on said tubular means for holding said normally retracted means in retracted position, said lock means being releasable by manipulation of said tubular means; a tubular member adapted for connection toa tubular stringr' clutch 'mea-ns connecting said tubular member to said tubular necting one of said cam members to said valve means, and means connecting the other of said lcam members to said tubular means.

15. A well tester: including tubular means having a seat. and adapted to be lowered in` a Awell bore on a tubular string; valve means in said tubular means for controlling fluid flow between the interior and exterior of said tubular means, comprising a housing having a side port therein, a sleeve valve adapted to be disposed over said port, means engageable with said sleeve valve to shift said sleeve valve to a position open ing said port, a valve element movable upwardly into engagement with said valve seat to prevent upward flow of fluid into said tubular means, a downwardly closing valve device in said tubular means below said valve element to prevent downward iiow of fluid from said tubular means, and means for shifting said valve element between open and closed positions, comprising an axial cam member and a follower member engageable therewith, means connecting one of said members to said valve element, and means connecting the other of said members to said tubular means.

16, A well tester; including tubular means having a valve seat and adapted to be lowered in a well bore on a tubular string; valve means in said tubular means for controlling uid flow between the interior and exterior of said tubular means, comprising a housing having a side port therein, a sleeve valve in said housing and having a seat, means releasably securing said sleeve valve to said housing and over said port, a first valve element above said sleeve valve and movable upwardly into engagement with said seat of said tubular means to prevent upward flow of fluid into said tubular means, a second valve element movable downwardly into engagement with said sleeve valve seat to prevent downward flow of iiuid from said tubular means through said sleeve valve, and means for shifting said rst valve element between open and closed positions, com- Y prising an axial cam member and a follower member engageable therewith, means connecting one of said members to said first valve element, and means connecting the other of said members to said tubular means.

1'7. A well tester: including tubular means having a valve seat and adapted to be lowered in a well bore on a tubular string; valve means in said tubular means for controlling fluid now between the interior and exterior of said tubular means. comprising a housing having a side port therein, a sleeve valve having a seat, means releasably securing said sleeve valve to said housing and over said port, a first valve member movable upwardly into engagement with said valve seat of said tubular means to prevent upward ow of fluid into said tubular means, a second Valve ele ment movable downwardly into engagement with said sleeve valve seat to prevent downward flow of fluid from said tubular means through said sleeve valve, and means for shifting said flrst valve element between open and closed position,

comprising an axial cam member and a. follower member lengageable therewith, means connectl ing one of said members to said rst valve ele ment, and means connecting the other of said membersto said tubular means.

REUBEN C. BAKER.

REFERENCES CITED The following references are of record inthe le of this fpatent:

UNITED STATES PATENTS Number Number Name Date Conner May 5, 1931 Montgomery Feb. 23, 1932 Humason Aug. 30, 1932 Howard Apr. 9, 1935 McKinley Apr. 16, 1940 Humason et a1. Apr. 30, 1940 Thornhill Aug. 20, 1940 Edwards Sept. 10, 1940 Pranger Jan. 7, 1941 Taylor et al. Oct. 24, 1946 FOREIGN PATENTS Country Date France 1930 

